The present disclosure relates to paper sheet conveying apparatuses and image forming apparatuses.
To image forming apparatuses, such as printers, facsimile apparatuses, copy machines, and multifunctional peripherals, paper sheet conveying apparatuses that convey paper sheets are mounted. As this type of paper sheet conveying apparatus, a paper sheet conveying apparatus that conveys paper sheets by rotating a plurality of conveying rollers which sandwich the paper sheet is known. Specifically, in the image forming apparatus, the paper sheet conveying apparatus is used to convey, to an image forming portion, paper sheets stacked in a sheet feed cassette, a manual feed tray, or the like.
In this type of paper sheet conveying apparatus, a stepping motor that rotates in synchronization with an inputted pulse signal is used as a driving source of the conveying roller. When the stepping motor is overloaded, an abnormal state called an out-of-step occurs in which the stepping motor does not rotate in synchronization with the inputted pulse signal, and the stepping motor may stop. Therefore, when the out-of-step occurs while a paper sheet is being conveyed, the conveying rollers stop and paper jam may occur. In conventional arts, when paper jam occurs, the image forming apparatus stops operating, and an error indicating that the paper jam has occurred is displayed, thereby prompting a user to remove a paper sheet jammed in the conveying rollers.
On the other hand, a technique is known in which, after an out-of-step occurs in a stepping motor that drives a belt for conveying paper sheets, driving of the stepping motor is restarted, to continuously convey the paper sheets by the belt.